USB 3.0 Q&A with VIA Labs

VLI tells us a little bit more about their USB 3.0 products

TODAY WE HAVE something a little bit different from or usual content, as we have a Q&A with Terrance Shih who is a PM at VIA Labs. We asked him some questions about VIA Labs, its USB 3.0 product line and how they see themselves positioned in the market, so with no further ado, here’s what he had to say.

S|A: Please introduce yourself and tell us a little bit about yourself and what you do at VIA Labs

VLI: My name is Terrance Shih, and I am a PM at VIA Labs. A PM is a combination of Product Manager and Project Manager, but there is also a dash of Marketing Representative and Product Specialist to spice things up. Traditionally, a PM is responsible for defining the features and specifications of a product, and is responsible for that product from engineering, application, and business perspectives for the duration of its lifecycle.

S|A: Please give us a little bit of background information about VIA Labs

VLI: VIA Labs was founded back in July of 2008, and is a wholly-owned subsidiary of x86 platform provider VIA Technologies Inc. Our core engineering teams have experience in developing other gigabit-speed serial link interface such as PCI Express, HDMI, and Display Port, and combined with VIA’s USB 2.0 experience in core logic and driver development, getting involved in USB 3.0 was a logical move. The original vision for VIA Labs was that it would be a smaller and thus more agile company, and would be better equipped to tackle a more rapidly changing marketplace while developing technology that would ultimately benefit VIA. For example, through the work on the VL800 Host Controller, VIA gains the knowhow to integrate USB 3.0 into future chipsets.

S|A: So far VIA Labs is the first and only company with a four port solution for USB 3.0, how come you decided so early on to make a solution that offered more than two ports?

VLI: Based on our experience with the USB 2.0 market, we figured more is better! For example, one of the markets we targeted from the beginning was the Add-in card market, which definitely appreciates having more ports, since motherboards have a limited number expansion slots and most customers will not add more than a single controller card. Also, based on our architecture, the design effort for building a 2 versus 4 port solution would have been similar. A secondary consideration for designing a 4-port Host solution right away was to jump-start the USB 3.0 ecosystem. Admittedly, the VL800 has taken longer than we would have liked, but in order for the standard to really take off, we need a large install base and a wide variety of compelling devices. It’s a Chicken vs Egg question, really. As host and device vendor, it behooves us to offer multi-port hosts and hubs so end-users have the freedom to choose how many and what types of USB 3.0 devices they’d like to use. Finally, it’s worth noting that we now also have a 2-port solution, in the form of the VL801.

S|A: What’s been the most difficult part when it comes to engineering a USB 3.0 host controller?

VLI: Pushing the speed limit always brings new challenges and USB 3.0 was no different. As speeds increase, design tolerances and signal integrity margins become tighter and higher-order parasitic effects that were safely disregarded become very significant. One of the biggest challenges in USB 3.0 in general is actually the physical layer, which is the lowest and most fundamental part of a network or bus. The physical layer comprises of the connectors, cables, and the actual technologies involved in sending and receiving raw data bits. This part is so challenging that some companies actually outsource this part of the design. We’re quite proud to say that we built every critical piece of our Host Controller, from the physical layer up to the drivers.

Hardware aside, the other large obstacle is the driver effort. USB 3.0 introduced xHCI, which is a new Host Controller Interface. If we left it like that, everything would be fine, but there has been a push to have xHCI handle USB 2.0 and 1.1 as well. Currently, we have EHCI and OHCI/UHCI to handle USB 2.0/1.1, but with the transition to xHCI, it’s been a big challenge to have xHCI work as seamlessly. Ironically, implementing USB 3.0 was relatively easy, but with billions of USB 2.0 and 1.1 devices in existence and given the fact that xHCI is different from EHCI and OHCI/UHCI, retaining transparent interoperability with USB 2.0 and 1.1 devices is a big challenge.

S|A: Your current host controllers support the xHCI 0.96 spec, however, back in May Intel ratified the xHCI standard to 1.0, will VIA Labs be offering solutions that support the xHCI 1.0 spec in the near future?

VLI: xHCI 1.0 support is definitely on our roadmap, but the differences between xHCI 0.96 and xHCI 1.0 are relatively minor. Considering that all of the USB 3.0 hosts sold to date are based on the xHCI 0.96, and these products lifecycles are not short (eg. Notebooks, desktops, embedded systems etc), xHCI 0.96 and xHCI 1.0 will need to co-exist for some time to come. Also, at this time, the USB-IF is not quite ready to test or certify xHCI 1.0-based host controllers.

S|A: How is VIA Labs positioning its products in the market compared to your competitors, specifically the other Taiwanese USB 3.0 host controller makers.

VLI: The acronym for VIA Labs, Inc. is VLI, which is what we print as the top-side marking on our chips. Unofficially, we were thinking that VLI could also stand for Value, Leadership, and Intelligence.

In terms of leadership, we have an unmatched track record. Of our shipping products, three of them are actually world’s firsts – VL810 is the world’s first and only USB 3.0 hub controller, VL800 is the world’s first 4-port USB 3.0 Host Controller, and VL750 is the world’s first and only 4-channel USB 3.0 to NAND flash controller and it is the only USB to NAND controller that has been certified by the USB-IF.

The point we wanted to drive by highlighting Intelligence is that from the ground up, our products are designed to offer a compelling value proposition. Besides the performance and reliability aspects that are expected of controller chips, we have spent a lot of effort in making our products easy to use while minimizing the overall BOM. An example of this effort is our choice of the QFN package for our IC’s—compared to BGA, the QFN package simplifies PCB layouts and allows for the possibility of 2-layer solutions, offers outstanding signal integrity characteristics, and has excellent thermal properties and better grounding.

S|A: So far the only USB-IF certified host controllers come from Renesas and Fresco Logic, despite yourselves and several of the other Taiwanese host controller manufacturers having had solutions ready for several months. What’s the reason behind the certification hold up?

VLI: We expect to be certified in early 2011, which is mostly in step with our internal product road map. The USB-IF has done an excellent job in developing the testing methodology and they have been working very closely with us for a while now to get the VL800 host controller certified. However, there are obvious limitations regarding how much time they can give us.

S|A: We’re hearing that the software stack has caused delay, at least for some of your competitors, has this been an issue for the VL800 series?

VLI: This isn’t really an issue for us because all our driver and firmware development is done in-house.

S|A: Is VIA Labs considering making drivers for other operating systems than Windows for the VL800 series?

VLI: Yes. We will focus on the Windows platform in the beginning, due to Windows’s overwhelming market share, but we are also eyeing Linux since it is growing in popularity with embedded systems. Another aspect that makes Linux attractive is that it’s the first major OS to have native USB 3.0 and xHCI support. With Windows and OSX, the user currently need to install third party drivers to enable USB 3.0 functionality, though we hope that a future service pack or update can make this unnecessary.

S|A: What advantages does the VL800 series of host controllers offer over your competitors?

VLI: We are proud to say that we’re currently the only company that offers a four-port host solution which allows board and system customers to give the end-user more USB 3.0 ports on their devices. We also fully support the USB Battery Charging Specification which enables rapid charging of USB portable devices e.g. smart phones, tablets, media players etc. From a manufacturing perspective, we have several distinct advantages such as excellent signal integrity and ease of implementation.

S|A: The four port VL800 still only uses a single PCI Express lane. With 5Gbps of bandwidth per port, a single PCI Express lane doesn’t offer enough bandwidth for full performance across four ports. Why did you decide to use a single PCI Express lane instead of say two or four?

VLI: We’ve considered doing a two or four PCIe lane solution, but we found that unless you were running multiple SSD’s, the single PCIe lane won’t be a bottleneck. The most common usage of USB 3.0 will be for external storage, and hard drives today peak at around 100 MB/s. Using a protocol analyzer, we’ve seen USB 3.0 working in bursts of up to 400MB/s. Also, if you look at mainstream platform offerings such as the Intel Core i3 and i5, there is a dearth of PCI Express Gen 2 lanes. At this point in time, adding additional lanes to our host controller would increase die size and power consumption without bringing tangible benefits, so we felt that it was a good compromise.

S|A: Will we be seeing host controller solutions from VIA Labs in the future that support more than one PCI Express lane for increased performance?

VLI: That’s a possibility, but not an option that we’re currently pursuing.

S|A: VIA Labs is also one of the first companies to offer a USB 3.0 hub in the shape of the VL810, we’re seeing this being integrated onto some high-end motherboards. Was this a market you expected for the VL810?

VLI: Yes, the VL810 was designed from the ground up for a variety of applications and implementations including motherboards, docking products and peripheral devices such as keyboards, monitors, external storage etc.

S|A: What advantages does the VL810 offer over competing solutions?

VLI: The VL810 is the only shipping USB 3.0 hub controller on the market. As such, we’ve had the opportunity to work with many device providers, system integrators, and the USB-IF to further enhance the VL810’s performance and interoperability characteristics.

S|A: The VL700 USB 3.0 SATA bridge controller was your first USB 3.0 product and seems to have gained a fair bit of popularity in the market. How does it compare to competing solutions and what sets it apart from the competition?

VLI: The VL700 was designed with a holistic approach with regards to overall system BOM and performance. It’s a mature and proven solution that hits a sweet spot in terms of speed and overall value.

S|A: The VL750 USB 3.0 to NAND Flash controller seems like it will be a very popular product, especially as there doesn’t appear to be that many competing solutions in the market. Can you tell us about any design wins based on the VL750?

VLI: The VL750 has been sampling for a few months now. Unfortunately I can’t give specific details, but products featuring the VL750 should be on shelves early next year.

S|A: How does the VL750 compare to competing solutions and does it have any upper performance limit, or is it limited to how fast the NAND Flash memory is?

VLI: The VL750 is the only certified USB 3.0 to NAND Flash controller on the market. We’ve optimized it for sequential read and write operations, which is the most common type of work load that USB flash drives encounter. The VL750 offers very compelling performance that should keep us ahead of the competition when it arrives.

S|A: The spec sheet for the VL750 on the VIA Labs website doesn’t mention ONFI support, does the VL750 support ONFI NAND Flash or was this deliberately not included?

VLI: The VL750 is compatible with NAND Flash from many vendors, and supports ONFI 2.2, but in asynchronous mode only. In an effort to simplify the design effort for our partners, instead of listing which specifications our controller supported, we prepared a list of recommended, commonly available modules.

VLI: Initially, the biggest challenge was the actual engineering effort. Now it seems the biggest challenge is coming up with unique product differentiators that give our partners and customers the edge in an increasingly competitive market. In the past, the “if you build it, they will come” approach was sufficient, but now, customer engagement and involvement is becoming increasingly important.

S|A: Are all your USB 3.0 solutions developed in-house or are you using some third party IP?

VLI: VIA Labs has developed all of the critical pieces in-house such as the Physical Layer and Drivers. The principle advantage of developing these things in-house is that we have full control over our development process, so we don’t have to worry about licensing fees or completely rely on a third party. With that said, we are using some third-party IP, but it’s for elements like the 8051 microcontroller and things related to the fabrication process.

S|A: Can you tell us something about the future of USB 3.0 products from VIA Labs?

VLI: Now that we’ve established a comprehensive range of USB 3.0 controllers, our future efforts will be focused on either further optimizations such as reducing power consumption, or adding features that improve usability and performance. We are also investigating new applications of USB 3.0.

S|A: How do you see the future development of USB 3.0? Many seem to think that due to lack of support from Intel, USB 3.0 won’t become a major interface for external devices, is this something that is a concern for VIA Labs?

VLI: We expect USB 3.0 will be fully supported and integrated into every mainstream computing platform in the near future. The reports of Intel dragging its feet are somewhat misleading, since this is exactly what happened when USB 2.0 was revealed. If you recall, when USB 2.0 launched, there was no native Windows OS support, and it took a few years before USB 2.0 devices arrived in mass. USB 3.0 is experiencing very rapid adoption and there will be great momentum next year.

S|A: With Intel’s Light Peak technology expected to be offering 10Gbps of bandwidth in theory, twice that of USB 3.0, do you believe USB 3.0 have a long term future as an external device interconnect if Intel was to launch Light Peak next year, however unlikely it seems?

VLI: We believe that Light Peak will not see wide-spread adoption, despite Intel’s or Apple’s best efforts. We see Light Peak more as a bus than a true interface, since it seems to be good way to piggyback multiple protocols through a single cable. Light Peak’s breakthrough application might be in the docking station segment, but it should be noted that in that particular use, Light Peak does not actually replace any ports. It basically moves them from the mobile device to the dock.

USB is the most successful interface in history and there are literally billions of devices in existence. In all likelihood, USB will become the longest-lived interface of all time! The only way for Light Peak to gain significant traction as a USB replacement is if hordes of end-users suddenly decided to replace all of their USB peripheral devices with those that supported Light Peak, but this is of course very unlikely.

S|A: Do you think we’ll see hybrid USB 3.0/Light Peak products in the future?

VLI: It’s possible. Strictly speaking, some of the early Light Peak devices demoed were actually USB 3.0 devices that were converted to make use of the Light Peak connector. While I don’t know for sure, I’d wager they were still running the USB 3.0 protocol, making them hybrid devices of a sort.

S|A: If you could re-design the USB 3.0 spec, what would you change to make it better?

VLI: Overall, I think USB 3.0 is very well thought out, but it could have benefited from a somewhat smoother roll out. For example, some of the most touted features such as UASP and the much needed Audio Video Class Drivers are either not available or not ready yet. Also, we don’t have widespread chipset integration or native Windows or Mac OS support at the moment.

S|A: Where do you see VIA Labs heading in the future, what other kind of products can we expect beyond USB3.0?

VLI: VIA Labs has a great deal to look forward to in 2011 as our new products enter mass production. For the very latest in USB 3.0 applications, you’ll have to join us at CES where we will be showcasing some very exciting new concepts.

We would like to thank Terrance for taking time to answer our questions and we’re looking forward to seeing what VIA Labs will be showing at CES.S|A

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